Apparatus for sealing a puncture by causing a reduction in the circumference of the puncture

ABSTRACT

Apparatus is provided for sealing a vascular puncture by causing a reduction in the circumference of the puncture tract through delivery of a closure agent into tissue surrounding the puncture tract. A resultant inflammatory response and volumetric increase cause the tissue to swell into the puncture tract, thereby sealing it.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/523,218 filed Oct. 19, 2005, which is an U.S. Nationalization of PCTInternational Application No. PCT/EP2003/008247, filed Jul. 25, 2003,which claims the benefit of U.S. Provisional Application No. 60/401,173,filed Aug. 1, 2002. The entireties of each of the foregoing applicationsare incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to apparatus for sealing punctures. Morespecifically, the invention relates to apparatus that may bepercutaneously inserted to seal a puncture by causing a reduction in thecircumference of the puncture.

BACKGROUND Background and Relevant Art

A large number of medical diagnostic and therapeutic procedures involvepercutaneous introduction of instrumentation into a blood vessel. Forexample, coronary angioplasty, angiography, atherectomy, stenting, andnumerous other procedures often involve accessing the vasculaturethrough placement of a catheter or other device in a patient's femoralartery or other blood vessel. Once the procedure is completed and thecatheter or other diagnostic or therapeutic device is removed, bleedingfrom the resultant vascular puncture must be stopped.

Traditionally, a medical practitioner applies external pressure to thepercutaneous entry site to stem bleeding until hemostasis has occurred(i.e. When the clotting and tissue rebuilding have sealed the puncture).This method, however, presents numerous problems. In some instances,this pressure must be applied for up to an hour or more during whichtime the patient is uncomfortably immobilized. In addition, there existsa risk of hematoma, since bleeding from the puncture may continue untilsufficient clotting affects hemostasis. Furthermore, application ofexternal pressure to stop bleeding may be unsuitable for patients withsubstantial amounts of subcutaneous adipose tissue, because the skinsurface may be a considerable distance from the puncture site, therebyrendering external compression less effective.

Another traditional approach to subcutaneous puncture closure involvesinternally suturing the vessel puncture. This method, however, comprisesa complex process and requires considerable skill by the medicalpractitioner.

Mechanical occlusion devices have been proposed for sealing vascularpunctures in U.S. Provisional patent application Ser. No. 60/400,658,filed Jul. 31, 2002, which describes a closure device having twoexpandable disks that sealingly compress a vessel or tissue surroundingthe puncture site. Advantageously, the two disks may be repositionedpost-deployment at the puncture without inflicting additional trauma tothe engaged vessel or tissue.

Apparatus and methods also are known in which a plug is introduced intothe vessel puncture, to cover the puncture and promote hemostasis.Various types of plugs have been proposed. One example is described inU.S. Pat. No. 5,061,274 to kensey, comprising a plug made fromanimal-derived collagen. Such a plug inserted into the puncture may bedislodged into the vessel during the healing process due to theapplication of pressure to the wound, potentially causing stenosis ofthe vessel. Furthermore, the presence of the plug within the punctureprevents re-access to the puncture site without potentially dislodgingthe plug into the vessel. Further still, there is a risk of unwantedadverse reaction to the animal-derived collagen.

In view of the drawbacks associated with prior art methods and apparatusfor sealing a vascular puncture, it would be desirable to provideapparatus that overcomes such drawbacks.

It would be desirable to provide apparatus for sealing a vascularpuncture by inducing a reduction in the circumference of the puncture.

It also would be desirable to provide apparatus for sealing a vascularpuncture that reduces a potential that a portion of a wound closuredevice will protrude into the vessel lumen.

It further would be desirable to provide apparatus for sealing avascular puncture that is easy to use.

It even further would be desirable to provide apparatus for sealing avascular puncture that permits re-access to the puncture site.

It still further would be desirable to provide apparatus for sealing avascular puncture that are biodegradable.

BRIEF SUMMARY

In view of the foregoing, it is an object of the present invention toprovide apparatus for sealing a vascular puncture by inducing areduction in the circumference of the puncture.

It also is an object of the present invention to provide apparatus forsealing a vascular puncture that reduces a potential that a portion of awound closure device will protrude into the vessel lumen.

It further is an object of the present invention to provide apparatusfor sealing a vascular puncture that is easy to use.

It even further is an object of the present invention to provideapparatus for sealing a vascular puncture that permits re-access to thepuncture site.

It still further would be desirable to provide apparatus for sealing avascular-puncture that are biodegradable.

These and other objects of the present invention are accomplished byproviding apparatus for sealing a vascular puncture by delivering anagent into tissue surrounding a puncture tract that induces a reductionin the circumference of the puncture and puncture tract. Morespecifically, the apparatus of the present invention induces reductionof the puncture diameter by delivering a closure agent into tissueimmediately surrounding the puncture tract to cause the tissue to swellinto and seal the puncture tract. the closure agent may comprise a waterswellable gel, collagen, a saline bolus, a granular slurry, aninflammatory substance, and/or a plurality of balloons.

A first embodiment of apparatus of the present invention comprises ahousing having a plurality of needles, and optionally, a shaft having anexpandable member disposed on its distal end. When expanded, theexpandable member engages an inner vessel surface distal to thepuncture. The proximal force transmitted by the expandable memberstabilizes the vessel wall and surrounding tissue during insertion ofthe needles.

An optional injection manifold may be fluidically coupled to aninjection port and the plurality of needles. an actuator coupled to theinjection manifold may be operable to cause the plurality of needles topenetrate into the subcutaneous tissue surrounding the puncture tract ina direction generally parallel to the puncture tract.

In accordance with one aspect of the present invention, the injectionapparatus also comprises a stop to limit distal advancement of theplurality of needles into the tissue surrounding the puncture tract. ina preferred embodiment, this may be associated with the position of theexpandable member in the puncture tract.

In an alternative embodiment of the present invention, apparatus may beprovided comprising a housing coupled to a plurality of needles thathave lengths shorter than that of the puncture tract, or that areconstrained such that a depth to which they may penetrate tissue is notgreater than the length of the puncture tract. Preferably, the housingis annular in shape and the plurality of needles are circumferentiallyarrayed. However, other configurations also are within the scope of thepresent invention. The apparatus is preferably configured such that thehousing limits a depth to which the needles may be advanced into thepatient's tissue by abutting the exterior of the patient, i.e. abuttingthe patient's skin, when the needles have been translated to theirmaximum depth proximal of the vessel. this reduces a risk of inadvertentinsertion of the needles into vessel V.

The apparatus optionally comprises a centering shaft configured forplacement in the puncture tract. The plurality of needles may beadvanced in unison with the centering shaft into the tissue and puncturetract, respectively, or may be advanced over the centering shaft afterthe centering shaft is already disposed within the puncture tract. Thisensures that the plurality of needles is centered about the puncturetract and thereby accurately punctures tissue surrounding the puncturetract.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the present invention, its nature and variousadvantages will be more apparent from the accompanying drawings and thefollowing detailed description of the preferred embodiments, in which:

FIG. 1 is a schematic side-sectional view of a vascular puncture tract;

FIG. 2A is a schematic perspective view, partially in section, ofapparatus of the present invention deployed to seal the puncture of FIG.1;

FIG. 2B is a schematic side-sectional view of the apparatus of FIG. 2A;

FIG. 3 is a schematic side view, partially in section, of an alternativeembodiment of an expandable member of the apparatus of the presentinvention in its deployed configuration;

FIGS. 4A and 4B are schematic side views, partially in section, of aplurality of needles of the apparatus of the present invention, the twoviews illustrating delivery of closure agent to tissue surrounding apuncture tract without and with, respectively, the use of the expandablemember of FIG. 3;

FIGS. 5A-5D are schematic side views, partially in section and/orcut-away, describing an exemplary method of using the apparatus of FIGS.1-4;

FIGS. 6A and 6B are schematic side views, partially in section,describing an optional step in using the apparatus of FIGS. 1-4;

FIG. 7A is a schematic side view, partially in section of an alternativeclosure agent of the apparatus of FIGS. 1-6;

FIG. 7B is a schematic perspective detail view of the closure agent ofFIG. 7A;

FIG. 8 is a schematic perspective cut-away view of an alternativeembodiment of the present invention; and

FIG. 9 is a schematic perspective view of another alternative embodimentof the present invention.

DETAILED DESCRIPTION

Upon completion of a medical diagnostic or therapeutic procedureinvolving percutaneous introduction of instrumentation into blood vesselV, removal of the instrumentation from the patient leaves puncture tractTR. As seen in FIG. 1, puncture tract TR extends through subcutaneoustissue T and vessel wall W, and terminates at puncture P. The apparatusof the present invention is directed to a device for sealing puncture Pby causing a reduction in the circumference of the puncture and puncturetract. Specifically, the device of the present invention involvesdelivering a closure agent into tissue T immediately surroundingpuncture tract TR to cause tissue T to swell into and seal puncturetract TR.

In a preferred embodiment of the present invention, the closure agentcomprises a biodegradable substance that may be delivered in a fluidstate, and that swells or increases in volume in the presence of water.A continual increase in the volume of the closure agent, when disposedwithin the tissue surrounding puncture tract TR, causes a consequentswelling of the tissue that decreases the circumference of puncture Puntil the puncture is closed.

One example of a closure agent suitable for use with the apparatus ofthe present invention is a hydrogel. A number of synthetic andanimal-based hydrogels are known in the art.

Alternatively, the closure agent may comprise an inflammatory substance.Injection of the inflammatory substance into tissue T surroundingpuncture tract TR causes a narrowing of the puncture by initiating alocalized inflammation response in tissue T due to the presence of theinflammatory substance, thereby causing localized swelling thatdecreases the circumference of puncture tract TR and puncture P untilthe puncture is closed.

One example of an inflammatory substance that may be used is coppersulfate. Described in The Merck Index, 12.sup.th Edition, (Budavari etal., Eds.) Merck Research Laboratories, Whitehouse Station, N.J., 1996,copper sulfate is a strong irritant that is soluble in water. Oneparameter that indicates the toxicity of copper sulfate is its LD.sub.50index, which is defined herein as the amount of a substance that issufficient to kill 50% of a population of animals. The LD.sub.50 forcopper sulfate, when administered orally to rats, is 960 mg/kg. Thus,when administered in low dosages as a closure agent in accordance withthe principles of the present invention, copper sulfate may providelocalized inflammation in the area surrounding puncture P, and yetholistically be well tolerated by the patient.

As yet further alternatives, the closure agent may comprise collagen, abolus of saline, which is resorbed into the tissue, a slurry formed fromgranules of a biocompatible substance, such as polyglycolic acid, and/oran expandable member, such as one or more inflatable balloons, to bedescribed in greater detail hereinbelow.

An illustrative embodiment of device 10 of the present invention isshown in FIGS. 2A and 2B, percutaneously disposed traversing puncturetract TR. Injection device 10 comprises housing 12, shaft 14, andinjection manifold 16. Shaft 14 is disposed to be axially translatablewith respect to housing 12 through Toughy-Borst valve 18, which isdisposed on the proximal end of housing 12, and through distal lumen 20,which is disposed in the distal end of housing 12. Toughy-Borst valve 18may be actuated to releasably lock shaft 14 to housing 12. Shaft 14 iscoupled to port 22, and is used to deploy and retract expandable member24 disposed on the distal end of shaft 14. Illustratively, expandablemember 24 is a disk-shaped balloon, although other structures such asmechanically expandable baskets, pledgets or super-elastic coils may beused. Port 22 may comprise, e.g., a luer valve, and be configured toreleasably couple to a standard inflation source (not shown), per seknown in the art. In the configuration shown in FIG. 2, expandablemember 24 has a diameter greater than the diameter of puncture P. Shaft14 also may comprise radiopaque band 27 disposed on the distal end ofthe shaft to provide visual guidance during insertion of apparatus 10when used with a fluoroscopy system, as is known in the art.

Manifold 16 comprises inlet port 28, and is in fluid communication withplurality of needles 30. As more clearly shown in the inset of FIG. 2A,each needle 30 has injection lumen 31 in fluid communication withmanifold 16, at least one injection aperture 32 disposed on the distalend of needle 30, sharp distal tip 35 shaped to penetrate subcutaneoustissue T, and an optional radiopaque marker 37 disposed in the vicinityof distal tip 35. Inlet port 28 may comprise, for example, a luercoupling that may be releasably coupled to a source of closure agent(not shown). Fluid communication among inlet port 28, injection manifold16, and lumens 31 permits closure agent introduced into inlet port 28 toflow into injection lumens 31, and through apertures 32 into the tissuesurrounding the puncture tract. Injection manifold 16 illustratively hasan annular shape, and is configured to be disposed around and slidealong shaft 14. Inlet port 28 extends from housing 12 through slot 33and may be coupled to actuator 34 concentrically disposed around lateralwall 36 of housing 12.

Along with inlet port 28, actuator 34 may be used to longitudinallytranslate manifold 16, subsequently translating needles 30 therewith.Translation of needles 30 is guided by plurality of needle lumens 38formed in a distal portion of housing 12. The length of slot 33 and therelative position of shaft 14 limit translation of needles 30. Shaft 14may include flange 40, which serves as a distal stop to limit distaltranslation of injection manifold 16. Flange 40 is positioned alongshaft 14 so that the distance between flange 40 and expandable member 24is slightly greater than the length of needles 30. Advantageously, thisensures that needles 30 may be disposed within tissue just proximal ofvessel wall W to deliver closure agent therein, without piercing vesselwall W. Stop 40 eliminates the need for visual confirmation of theposition of needles 30 and apertures 32 prior to injection of theclosure agent. Alternatively, if visual confirmation is desired,observation of radiopaque markers 27 and 37 respectively disposed onshaft 14 and needles 30 may be made using conventional fluoroscopictechniques.

It will be evident to one of ordinary skill in the art that apparatus 10of the present invention may comprise more than the two needles, asshown in the figures, or as few as a single needle. If puncture tract TRand puncture P are substantially circular in shape, additional needles30 may be disposed to penetrate subcutaneous tissue T so that closureagent may be injected into the tissue surrounding puncture tract TR in acircular pattern. If the puncture tract and the puncture is of anothergeometry, needles 30 may be configured to penetrate the subcutaneoustissue in a pattern that complements that geometry.

In accordance with one aspect of the present invention, expandablemember 24 is disk-shaped to provide a substantially flat profile againstinner vessel surface W′ when deployed and engaged therewith. This flatprofile reduces disturbance to blood flow, and, in a manner described ingreater detail below, expandable member 24 may deflect vessel wall W tofacilitate delivery of the closure agent. In an alternative embodiment,expandable member 24 may comprise a spherical shape, as illustrated inFIG. 3.

In accordance with another aspect of the present invention, expandablemember 24 is expected to reduce “tenting” of tissue T and vessel wall Winto the lumen of vessel V. As used herein and shown in FIG. 4A,“tenting” refers to a tendency for tissue T surrounding puncture tractTR and vessel wall W surrounding puncture P to deflect into the lumen ofvessel V when the tissue begins to swell after the injection of closureagent A therein. In the present invention, “tenting” of the tissue intothe lumen of vessel V may be reduced by application of a proximallydirected force to shaft 14, which in turn engages expandable member 24against inner vessel surface W′. Accordingly, as shown in FIG. 4B, anydeflection of tissue T and vessel wall W is directed in the proximaldirection away from the lumen of vessel V. This reduces a risk thatvessel V at least partially will be occluded from distal protrusion oftissue T and vessel wall W. Furthermore, when expanded and engagedagainst inner vessel surface W′, the proximal force transmitted byexpandable member 24 is expected to stabilize the vessel wall andsurrounding tissue during insertion of needles 30.

Referring now to FIG. 5, an exemplary method of using apparatus 10 ofthe present invention is described. First, housing 12 is placed againsta patient's skin with distal lumen 20 aligned with puncture tract TR.Alignment may be facilitated if shaft 14 is slightly advanced out ofdistal lumen 20 so that it may be inserted into puncture tract TR. Shaft14 then is distally advanced until expandable member 24 is introducedinto the lumen of vessel V. This position may be determined byobservance of radiopaque band 27 disposed on the distal end of shaft 14,or by tactile feedback.

Once expandable member 24 is disposed within vessel V, expandable member24 is deployed to its disk-shaped configuration. A proximal force thenmay be applied to shaft 14 to forcibly engage expandable member 24against inner vessel surface W′, providing immediate hemostasis.

After expandable member 24 is engaged to vessel wall W, Toughy-Borstvalve 18 is actuated to lock shaft 14 relative to housing 12, therebymaintaining forcible engagement of expandable member 24 to inner vesselsurface W′. This in turn locks the longitudinal position of flange 40attached to shaft 14, and defines the maximum distal position to whichneedles 30 may be translated. Advantageously, the maximum distalposition of needles 30 is designed to coincide with introduction ofneedles 30 into tissue surrounding the puncture tract just proximal ofvessel wall W. Alternatively, instead of using Toughy-Borst valve 18, acontinual proximal force may be applied to shaft 14 to maintain theposition of shaft 14 with respect to housing 12.

Injection manifold 16 then may be translated in the distal direction bydepressing actuator 34. Since needles 30 are affixed to manifold 16,distal force applied to actuator 34 is transmitted to needles 30,thereby penetrating subcutaneous tissue T with plurality of needles 30.During insertion of needles 30, the proximal force transmitted byexpandable member 24 to inner vessel surface W′ stabilizes vessel wall Wand tissue T. As discussed above, injection manifold 16 may be actuatedin the distal direction until manifold 16 contacts flange 40. At thisposition, needles 30 have penetrated into tissue T just proximal ofvessel wall W.

Inlet port 28 then is coupled to a source of closure agent A, such as asyringe (not shown), and the closure agent then is introduced throughneedles 30 into the tissue surrounding puncture tract TR. Depending onwhether a biodegradable substance such as a water swellable gel, aninflammatory substance such as copper sulfate, or a bioresorbablesubstance such as saline or a slurry, is introduced, puncture tract TRwill decrease in circumference as a result of swelling of tissue T frominflammation thereof and/or a volumetric increase. As discussed withrespect to FIG. 4, the proximal force applied to vessel wall W fromengagement of expandable member 24 to inner vessel surface W′ proximallydeflects tissue T surrounding puncture tract TR as the tissue swells,thereby reducing a potential that the tissue will protrude into thelumen of vessel V. This imposed force establishes a propensity for anyadditional swelling of tissue T also to “tent” in the proximal directioneven after expandable member 24 is contracted and removed from puncturetract TR.

After tissue T has sufficiently swelled so that blood does not flow frompuncture tract TR, expandable member 24 is contracted and disengagedfrom inner vessel surface W′. Shaft 14 is released from Touhy-Borstvalve 18, and a proximally directed force is applied to shaft 14 toretract shaft 14 and expandable member 24 from puncture tract TR. Sinceinjection manifold 16 is in contact with and proximally disposedrelative to flange 40, proximal retraction of shaft 14 also retractsneedles 30. It should be understood that shaft 14, expandable member 24and needles 30 may alternatively be removed as soon as closure agent Ahas been introduced into the tissue surrounding puncture tract TR.

After shaft 14 is removed, the compliancy and continual swelling oftissue T causes the vessel wall to pervade the space formerly occupiedby shaft 14 within puncture P and puncture tract TR, thereby sealing thepuncture and puncture tract. Any further “tenting” of tissue T andvessel wall W also is expected to deflect in the proximal directionpursuant to the propensity established by the previously appliedproximally directed force that engaged expandable member 24 to innervessel surface W′.

If puncture tract TR is not disposed substantially orthogonal to vesselV, as illustrated in FIG. 6, the proximal force applied to shaft 14 toforcibly engage expandable member 24 against inner vessel surface W′locally may deflect vessel wall W so that the vessel wall in theimmediate vicinity of puncture P is disposed substantially orthogonal topuncture tract TR. This configuration ensures that needles 30 do notpenetrate into vessel wall W, expandable member 24, or vessel V.Accordingly, expandable member 24 preferably has sufficient strength tolocally deflect the vessel wall in the manner shown in FIG. 6B.

Apparatus 10 of the present invention presents numerous advantages overpreviously known systems. First, in contrast to previously known woundclosure devices described above, the present invention significantlyreduces a risk that the wound closure device may become dislodged into alumen of vessel V, because the closure agent is injected directly intotissue T surrounding puncture tract TR, not directly into puncture tractTR. Accordingly, this eliminates a potential mode for a thrombotic orembolic event. Furthermore, the proximally directed force that engagesexpandable member 24 against inner vessel surface W′ establishes apropensity for tissue T and vessel wall W to “tent” in the proximaldirection when the tissue swells from the injected closure agent,thereby preventing any protrusion into the lumen of vessel V that maydisturb blood flow and serve as a site for thrombosis or embolism.

Moreover, the apparatus of the present invention is expected to permitre-access to the puncture tract since the present invention does notimplant any structures therein. Accordingly, other diagnostic ortherapeutic devices may be reinserted into puncture tract TR to accessvessel V so that additional diagnostic or therapeutic procedures may beperformed, thereby eliminating the need to create additional puncturesites.

Referring now to FIGS. 7A-7B, an alternative closure agent for use withdevice 10 is described. Device 50 is similar to device 10, except forthe inclusion of plurality of balloons 52 disposed over apertures 32 inthe distal region of needles 30. In the present embodiment, rather thaninjecting a closure agent directly into tissue T surrounding puncturetract TR, a decrease in the circumference of the puncture tract isachieved through inflation of balloons 52 within tissue T, whichtemporarily increase the volume of the tissue, causing the tissue toswell into the puncture tract, thereby decreasing the circumference ofthe puncture tract. Balloons 52 may be made of fluid-impermeable elasticmaterial, such as rubber.

In its deployment configuration, each balloon 52 is disposed around itsassociated needle 30, as shown in FIG. 7B. Accordingly, when tips 35 ofneedles 30 penetrate into tissue T, balloons 52 also are introduced intothe tissue. Once needles 30 have been disposed within tissue T in thesame manner as that described above with respect to FIGS. 5A-5C, astandard inflation source, e.g., a syringe (not shown), is fluidicallycoupled to inlet port 28 so that inflation fluid, such as air, water orsaline, may be injected into injection manifold 16 for delivery toballoons 52 through needles 30 and apertures 32.

Inflation of balloons 52 affects a volumetric increase in tissue T thatcauses the tissue to swell into puncture tract TR, thereby decreasingthe circumference of puncture P. If expandable member 24 is provided atthe distal end of shaft 14, a proximal force may be applied to shaft 14,as discussed hereinabove, to engage expandable member 24 to inner vesselwall W′, thereby-proximally deflecting tissue T as the tissue swells.After a period of time during which blood ceases to flow from puncturetract TR, balloons 52 may be deflated and retracted from tissue T alongwith needles 30 and shaft 14.

Alternatively, if expandable member 24 is not provided to facilitatedetermination of the maximum distal depth to which needles 30 may betranslated within tissue T, radiopaque markers 37 disposed at the distaltip of needles 30 may be used along with conventional fluoroscopictechniques. As yet another alternative, the lengths of needles 30 may beselected so that the needles will not penetrate the vessel.

In a further alternative embodiment of device 10, injection port 28,injection lumen 31 and apertures 32 may be omitted. Rather thaninjecting a closure agent or inflation fluid into needles 30 viainjection port 28 and manifold 16, needles 30 may be pre-coated with aninflammatory substance that will dissolve upon exposure to the fluidswithin tissue T, releasing the inflammatory substance to cause aninflammation response that swells the tissue into the puncture tract.

Referring now to FIG. 8, an alternative embodiment of the presentinvention is described, wherein device 70 may be provided comprisingplurality of needles 30 disposed in fluid communication with manifold 72having injection port 74 that may be fluidically coupled to a source ofclosure agent, e.g., one or more syringes (not shown). As with device10, each needle 30 has injection lumen 31 in fluid communication withaperture 32 disposed on distal tip 35. Manifold 72 preferably isannularly shaped with central bore 76 that may be translatably disposedaround optional centering shaft 78. While FIG. 8 shows an annularmanifold having a circumferential array of needles, it will be evidentto one of ordinary skill in the art that other shapes and configurationsmay be provided without departing from the scope of the invention.

Device 70 limits a maximum depth to which needles 30 may be advancedinto tissue T by providing needles of a specified length that is not aslong as the length of the puncture tract. Alternatively, the maximumdepth may be limited by specifying the distance that needles 30 mayextend beyond manifold 72. Preferably, when needles 30 are inserted totheir maximum depth, manifold 72 abuts the exterior of the patient,i.e., the patient's skin. Such depth may, for example, be limited toless than 5 cm. This depth is provided only for the sake of illustrationand alternative depths will be apparent to those of skill in the art.Limiting the depth to which needles 30 may be inserted into tissue T isexpected to reduce a risk of inadvertent insertion of needles 30 intovessel V.

The apparatus optionally may comprise centering shaft 78 that may betranslatably disposed within central bore 76 of manifold 72 and withinpuncture tract TR. Plurality of needles 30 may be advanced in unisonwith centering shaft 78 into tissue T and puncture tract TR,respectively, in which case centering shaft 78 optionally may be formedas an integral part of device 70. Alternatively, plurality of needles 30may be advanced over centering shaft 78 after centering shaft 78 hasalready been disposed within puncture tract TR. Both embodiments centerneedles 30 for accurate penetration thereof into tissue T surroundingthe puncture tract.

Centering shaft 78 may incorporate optional central lumen 80 that may beused to determine the depth of puncture tract TR so that an appropriatemaximum depth to which the needles may be advanced or an appropriatelength of needles 30 may be chosen. Specifically, centering shaft 78 maybe inserted into puncture tract TR until blood from vessel V backbleedsinto lumen 80. This indicates that the distal end of central shaft 78(not shown) is disposed just proximal to vessel V, or, alternatively,that the distal end of central shaft 78 is disposed at the distal end ofpuncture tract TR. Indicia 82 disposed on the proximal end of centralshaft 78 then may be noted to determine the depth of puncture tract TR,or alternatively the maximum depth/length of needles 30 that may be usedto avoid inadvertent penetration of needles 30 into vessel V.Accordingly, the present invention preferably provides a multiplicity ofneedle lengths. Alternatively, the distance of needles 30 extendingbeyond manifold 72 may be adjustable.

As in the preceding embodiments, the closure agent may include a waterswellable gel, collagen, an inflammatory substance, a saline bolus,and/or a granular slurry of a biocompatible substance. Alternatively,the closure agent may comprise a plurality of balloons affixed to thedistal ends of needles 30 over apertures 32. Inflation fluid may beintroduced into the balloons through injection port 74 and manifold 72.

In a further alternative embodiment of the present invention, injectionmanifold 72 and injection port 74 may be omitted. Device 90 comprisessolid housing 92 to which plurality of needles 94 are affixed. Device 90also may comprise optional centering shaft 78 having central lumen 80and indicia 82. Centering shaft 78 may be formed integrally with device90 or may be provided as a separate element. As in the previousembodiment, centering shaft 78 may be used to align plurality of needles84 with puncture tract TR, and central lumen 80 and indicia 82 may beused to determine the length of puncture tract TR and thereby themaximum length of needles 94 that may be used to avoid inadvertentpenetration thereof into vessel V. Alternatively, the distance ofneedles 94 extending beyond housing 92 may be adjustable, thereby makingthe maximum depth to which the needles may be advanced into tissue Tadjustable.

Device 90 differs from the previous embodiments in that needles 94 aresolid, i.e. have no injection lumen. To deliver a closure agent totissue T surrounding puncture tract TR, needles 94 are pre-coated withan inflammatory substance that dissolves within tissue T uponpenetration thereof and exposure to the fluids therein. A resultantinflammation response swells tissue T into puncture tract TR, therebyclosing puncture P.

While preferred illustrative embodiments of the present invention aredescribed above, it will be apparent to one skilled in the art thatvarious changes and modifications may be made therein without departingfrom the invention. For example, additional closure agents, per seknown, will be apparent. The appended claims are intended to cover allsuch changes and modifications that fall within the true spirit andscope of the invention.

1-23. (canceled)
 24. A method for treatment of a puncture wound in apuncture tract, the method comprising: inducing localized swelling oftissue surrounding the puncture tract by delivering a closure agentcomprising a biodegradable substance or inflammatory substance thatcauses a localized inflammation response to the tissue in the puncturetract.
 25. The method of claim 24, wherein the closure agent comprises awater-swellable gel, collagen, a saline bolus, a slurry of abiocompatible substance and combinations thereof and/or an inflammatorysubstance.
 26. The method of claim 24, wherein the delivery is done withan apparatus for sealing a puncture tract disposed within tissue, theapparatus comprising: a housing; and a plurality of needles coupled tothe housing, the plurality of needles configured to penetrate tissuesurrounding the puncture tract to deliver the closure agent into thetissue, thereby sealing the puncture tract.
 27. The method of claim 26,wherein the apparatus is further comprising an expandable memberconfigured to be disposed within the puncture tract to stabilize thetissue during insertion of the plurality of needles.
 28. The method ofclaim 26, wherein the apparatus is further comprising a stop configuredto limit translation of the plurality of needles into the tissue. 29.The method of claim 26, wherein apparatus is further comprising anactuator coupled to the plurality of needles for selective translationof the plurality of needles.
 30. The method of claim 26, wherein theclosure agent is coated onto the plurality of needles.
 31. The method ofclaim 26, wherein each one of the plurality of needles of the apparatuscomprises a distal tip configured to penetrate the tissue, a distalaperture, and a lumen that couples the distal aperture to a source ofclosure agent.
 32. The method of claim 26, wherein the housing of theapparatus further comprises a manifold having an inlet port, themanifold in fluid communication with the plurality of needles.
 33. Themethod of claim 26, wherein the plurality of needles of the apparatusare coupled to the housing in a predetermined array.
 34. The method ofclaim 26, wherein the apparatus is further comprising a centering shaftadapted for placement in the puncture tract.
 35. A closure agent for thetreatment of the puncture wound of a puncture tract disposed withintissue, the closure agent comprising: a biodegradable substance that maybe delivered into a tissue in a fluid state to induce localized swellingof tissue surrounding the puncture tract.
 36. The closure agent of claim35, wherein the closure agent comprises a water-swellable gel, collagen,a saline bolus, a slurry of a biocompatible substance and combinationsthereof and/or an inflammatory substance.
 37. The closure agent of claim35, wherein the closure agent is a pharmaceutical formulation.
 38. Aclosure agent for the treatment of the puncture wound of a puncturetract disposed within tissue, the closure agent comprising: aninflammatory substance that may be delivered into a tissue in a fluidstate to induce localized swelling of tissue surrounding the puncturetract.
 39. The closure agent of claim 38, wherein the closure agentcomprises a water-swellable gel, collagen, a saline bolus, a slurry of abiocompatible substance and combinations thereof and/or an inflammatorysubstance.
 40. The closure agent of claim 38, wherein the closure agentis a pharmaceutical formulation.